1. Field
Embodiments relate to a light emitting module and a lighting unit including the same.
2. Background
Light emitting devices, such as light emitting diodes or laser diodes, using Group III-V or II-VI compound semiconductor materials may produce various colors such as red, green, blue, and ultraviolet, thanks to development of thin film growth technologies and device materials. In addition, these light emitting devices may produce high-efficiency white light using fluorescent materials or through color mixing and have advantages, such as low power consumption, semi-permanent lifespan, rapid response time, safety, and environmental friendliness, as compared to conventional light sources, such as fluorescent lamps and incandescent lamps.
Therefore, such light emitting devices are increasingly applied to transmission modules of optical communication units, light emitting diode backlight units substituting for cold cathode fluorescence lamps (CCFLs) constituting backlight units of liquid crystal display (LCD) devices, lighting apparatuses using white light emitting diodes substituting for fluorescent lamps or incandescent lamps, headlights for vehicles, and traffic lights.
FIG. 1 is a schematic plan view of a conventional light emitting module 10.
The light emitting module 10 of FIG. 1 includes a plurality of light emitting devices 32, 34, 36, 38, 42, 44, 46 and 48 and a control circuit 20. Each of the light emitting devices 32, 34, 36, 38, 42, 44, 46 and 48 includes a plurality of light emitting structures connected in series. In this regard, the control circuit 20 controls the light emitting devices 32, 34, 36, 38, 42, 44, 46 and 48 to turn on and off according to level of a driving voltage applied from the outside. That is, the light emitting devices 32 and 42 are turned on when the level of the driving voltage is low, the light emitting devices 32, 34, 42 and 44 are turned on as the level of the driving voltage gradually increases, the light emitting devices 32, 34, 36, 42, 44 and 46 are turned on as the level of the driving voltage further increases, and all the light emitting devices 32, 34, 36, 38, 42, 44, 46 and 48 are turned on when the level of the driving voltage reaches a certain level.
Even though light emitting devices are sequentially turned on as described above, uniformity ratio of illumination and power consumption of the light emitting devices 32, 34, 36, 38, 42, 44, 46 and 48 of the conventional light emitting module 10 are not constant due to the disposition thereof as illustrated in FIG. 1.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.